import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

data = {
    "grammer": ["Python", "C", "Java", "GO", np.nan, "SQL", "PHP", "Python"],
    "score": [1, 2, np.nan, 4, 5, 6, 7, 10]
}
df = pd.DataFrame(data)
df = df.rename(columns={'score': 'popularity'})
print(df['grammer'].value_counts())

